This invention relates to a sampler for measuring a characteristic of a material or product flowing in a path; and, in particular, a sampler for measuring the moisture content of a sampling of grain flowing within a grain dryer.
Grain moisture samplers are typically mounted adjacent to an output path of a grain dryer. The sampler receives a portion of the grain moving toward the outlet discharge of the dryer and presents the grain for moisture measurement. A moisture sensor of the sampler measures and provides an indication of grain moisture. In typical configurations, grain falls into the sampler by gravity and flows out of the sampler by gravity or some mechanical means (i.e., small auger, etc.) The moisture sensor is positioned at some point in the sampler to measure the moisture of the entrapped grain. After being measured for moisture, the grain is returned to the outlet path of the dryer. It will be understood that the moisture sensor indicates the moisture of the dried grain as it is conveyed from the grain dryer. The output of the moisture sensor is sensed by the control system and is used to control the rate (speed) of the metering rolls so as to dry the grain a desired amount.
Due to the position of the sampling opening and the use of gravity infeed to the sampling opening, moisture samplers often are not located in an ideal position and collect foreign material or fines. These foreign material or fines negatively impact the accuracy of moisture measurements. Furthermore, due to spatial constraints and the typical use of inclined augers to move material through the sampler to the outlet, the sampler may not be emptying of sampled grain or foreign material at an appropriate speed. If the auger moves too fast, the moisture sensor may not be fully immersed in a consistent grain mass. Conversely, if the auger moves too slowly, the sensor may not be measuring grain representative of the current flow of grain. Accurate moisture measurement is further complicated by the variation in drying rates during dryer operation.
There is a need for farmers or other grain operators to have grain samplers that accommodate low and high material flow rates without compromising the accuracy of the measurements. Additionally, there is a need for samplers which must be able to reduce the introduction of fines or other debris toward the sensor so that a more representative grain sample to be measured.
Corresponding reference characters represent corresponding parts throughout the various views of the drawings.